1. Field of the Invention
This invention relates to devices and procedures for their use in an arthroscopic surgical procedure involving forming a straight ligament tunnel in a procedure for replacing a knee anterior cruciate ligament determining tunnel lengths and distance across the knee intra articular joint for selecting an appropriate length of a replacement ligament.
2. Prior Art
The present invention is in a device and its use with a surgical procedure involving formation of a straight tunnel in the distal femur and proximal tibia for replacing a patient's anterior cruciate ligament. The invention for use for conveniently locating a point on the surface of a patent's distal femur in their intercondylar notch that is to be a femoral tunnel end for measuring the distance between the points of origin of the anterior cruciate ligament, and the lengths of the femoral and tibial tunnel sections of the straight for selecting of a proper length of a replacement ligament. The located point to receive a straight pin turned therein to serve as a guide to receive one or more cannulated drills turned thereover to form a straight femoral tunnel section that is an extension of a tibial tunnel formed from the through proximal tibial, exiting within the knee intra articular joint. In which tunnel formation, the drilled hole or tunnel will pass through femur and tibia points of ligament origin. The prepared straight hole or tunnel is then for receiving the selected natural or prosthetic ligament fitted and secured therein in a surgical procedure for replacing a knee anterior cruciate ligament.
In the field of arthroscopic surgery, a procedure has recently been developed where, with a patient's knee bent at appropriately ninety degrees (90.degree.), a straight tunnel is formed through the tibial tuberosity, extending across the anterior cruciate points of origin in the intra articular joint on the proximal tibia and distal femur surfaces, and into the femur endosteum. Thereafter, an end of a replacement ligament, that is either a natural or prosthetic ligament, is fitted through the tibial opening to travel along the tunnel for mounting in the femur endosteum. One such use of a straight tunnel and mounting for an anterior cruciate ligament in the femur endosteum end thereof is shown in an earlier patent of the present inventor and others, Clark, et al, U.S. Pat. No. 5,266,075. Also, other examples of such straight tunnel formation procedures and a use of connectors for endosteally mounting a ligament end in a femoral tunnel section are shown in patents to Goble, et al, U.S. Pat. Nos. 4,772,286; 5,129,902 and 5,147,362. Further, a number of drill guides for forming such straight tibial and femoral tunnel sections in an arthroscopic surgical procedure are shown in patents to Goble, et al, U.S. Pat. Nos. 4,985,032; 4,901,711; 5,152,764; and 5,234,434. Also, another Goble U.S. Pat. No. 5,314,429, shows a guide for guiding drilling to a location along such straight ligament tunnel. None of which connectors and drill guide arrangements, however, show an arrangement for measuring the distance from the ligament points of origin and tunnel section lengths from the proximal tibia to a location in the distal femur for selecting an appropriate length of replacement ligament.
Additional to the Goble, et al drill guides, as set out above, there are a number of instruments for use in arthroscopic surgical procedures for guiding drilling to a location in a patient's knee. For example, U.S. Pat. Nos. 4,535,768; 4,672,957; 4,708,139; 4,739,751; 4,781,182; 4,787,377; 4,823,780; and 4,920,958, show examples of drill guides for forming a hole into a knee to a location therein that a pointer end of an arm of the drill guide is located. None, however, provide an arrangement, as does the present invention, for both locating a point on a distal femur surface as a ligament point of origin that aligns with a drill tube of the invention that has been fitted into a tibial tunnel, and for measuring the distance between the tibial tunnel end in the intra articular joint and that located point for selecting an appropriate length of replacement ligament. Further, which projecting wire end can be used to mark the location on the femur that then receives a k-wire that is turned into the distal femur to receive one or more cannulated drills turned therealong. The cannulated drills form a straight hole into the distal femur to receive a replacement anterior cruciate ligament, that is either natural or prosthetic, fitted therein. The length of which femoral tunnel section is itself easily determined by a subtraction of the length of the tibial tunnel section determined off from a scale marked on a drill guide and the distance across the intra articular joint between the ligament points of origin from the length of the drill turned into the distal femur the forms the femoral tunnel section.